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When I first loaded Nano saver onto my Linux machine (via Git hub), I had to enable "DIALOUT" under my group to establish permission to use the USB port to communicate with the NANO-VNA...

It looks OK, it's showing the baseband width (in Hz) and the number of sampled points OK.

Could you explain exactly what's not working DMR, what is it you're seeing wrong I wonder ?

Thank you for adding the LOGMAG one function to the software.
Now the second graph does not interfere with viewing and measurements.

I downloaded firmware with SD card support.
This area does not work on the display where the screenshot is taken.
The save function s1p, s2p in the menu works.

Yes I've just included DiSlords SD card updates into the code, though I can't test it myself as my little NanoVNA-H does not have an SD card slot fitted.

Here's the latest version with hopefully working SD card saves.

Do you intend to work on FW with SD card support?
I tested your FW and missed this option.
Grateful for your work.

A hint: while using FatFs (as it is with the H4 firmware) always do format your SDcards with



Igor

Hi,
You can also visit this website about ferrites:


The first ferrite measurements with nanoVNA were discussed by forum members here: /g/nanovna-users/message/6996 and in subsequent discussions. (/g/nanovna-users/topic/nanovna_saver_0_2_0/54247421?p=Created,,,20,1,20,0&jump=1)

73, Gyula HA3HZ
--
*** If you are not part of the solution, then you are the problem. ( ) ***

Yes no problem DMR.

Might take me a while for the that PC software to get useful though as I was only originally doing it for testing the firmware, but if people want to use it as a proper piece of software I'll continue to write it, I'll release the source code when it's a bit tidier as it's a bit messy at the moment. It's only for Windows though, have given up on writing multi-platform C++ PC software.

On Saturday 11 July 2020 05:26:07 pm DougVL wrote:

On Fri, Jul 10, 2020 at 03:05 PM, Roy J. Tellason, Sr. wrote:

Having a recently acquired NanoVNA-H4, and having a bunch of unmarked toroid
cores (some with windings, some without), I'd sure be interested in hearing
more about how you do this...

Check this link (if it works!)

It's supposed to be an article by w6rmk, on his earthlink web site. Which I can't find directly - must have gotten the page thru facebook.

Or google "Identifying Mystery Ferrites", which might get you there.

Did that, and came up with a link home.earthlink.net/~w6rmk/ferrite.htm, which seems to be awfully slow to load for some reason. Eventually it timed out. Retrying didn't help. That really long link got me to the same place, with the same result.

Also find a PDF by Owen Duffy, on his web site, the article "A method for estimating the impedance of a ferrite toroidal inductor at RF". Section 3, on the second page, is "Identifying ferrite materials", with a chart. You find the frequency where a 1-turn coil's R=X and get the mix number from the chart.

That one comes back with *one* result, a link to scribd, which won't let me see the whole document or download it. I don't use that site, don't like it, and have already had to issue them a couple of takedown notices when some of my stuff ended up there. That's using duckduckgo, while google came back with a hit on , which I downloaded.

There is a similar (but much shorter) page at

Got that one, too.

I have these articles printed out for easy access when I did some toroid checking.

Doug

Thanks for the links!

--
Member of the toughest, meanest, deadliest, most unrelenting -- and
ablest -- form of life in this section of space, ?a critter that can
be killed but can't be tamed. ?--Robert A. Heinlein, "The Puppet Masters"
-
Information is more dangerous than cannon to a society ruled by lies. --James
M Dakin

Vaclav,

I dropped some notes in the file section of this group, at /g/nanovna-users/files/Nano%20VNA%20Saver. The file is *nanoVNA-H4 software support under Ubuntu.pdf* (/g/nanovna-users/files/Nano%20VNA%20Saver/nanoVNA-H4%20software%20support%20under%20Ubuntu.pdf).

The approach described works with a nanoVNA-H4, and hopefully a nanoVNA-H. Essentially, a Python VM (virtual machine) is set up so that NanoVNA-Saver runs in its own isolated Python environment, avoiding interference to/from the rest of the Python needed to keep the OS running sweetly. A script is used to enter the Python VM, and then to exit the VM after NanoVNA-Saver itself exits. Then all is well.

HTH, 73, Stay Safe,

Robin, G8DQX

PS: It took me a while to find the answers, and one learnt about Python VMs.

As I receive the post of the group by email, I do receive them all with links on the bottom of the email.

-=-=-=-=-=-=-=-=-=-=-=-
Groups.io Links: You receive all messages sent to this group.

View/Reply Online (#15084): /g/nanovna-users/message/15084
Mute This Topic: /mt/xxxxxxxx/xxxxxxxx
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Learn about the NanoVNA in the following forum areas:
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Knowledge-based Wiki: /g/nanovna-users/wiki


As you can see, you can mute the topic. I did it myself so I wont receive any answer to my message.

Somethimes using the tools we have at hand is so easy...

The circuit shown by yvandelaserge will allow a good measurement of the common mode impedance of the choke provided the input impedance of the VNA's CH1 is accurately known. However, the common mode impedance alone doesn't say a thing about the common mode rejection that will be achieved in the application. For that, you also need to know the common mode impedances on both the source side and the load side. The final result could range from very good CMRR down to very poor CMRR, depending.

Dana

Roger,
Forgot to comment on what Kurt wrote. Yes. I remember that discussion but the phase reference will now be on the ch1 side of the 10 dB pad adding more off set to the actual phase shift thru the DUT. The accuracy of the source and load Z is still an issue. In the fall and winter I will go back to this stuff again and test a DUT on other instruments to see how they agree with the Nano using the thru S21 methods. I retired in '16 but then went back to work three more times on a part time basis so I'll have more time later in the year as I am finally finished.....fully retired.
Pete

Hi Roger,
I would say the reference plane is as show if a full two port cal was done but the Nanovna can not do a full two port cal. This makes me think that the phase reference is actually inside the VNA at Ch1's mixer. The Nanovna is like having a house with 1 and 1/2 bathrooms:)
Pete

HI OneOfEleven,
If possible, please add a display of only one graph (LOGMAG S21) in the menu.

It appears the original site is down or no longer exists.

In that case, use the Wayback Machine (aka Archive.org)

On Fri, Jul 10, 2020 at 03:05 PM, Roy J. Tellason, Sr. wrote:

Having a recently acquired NanoVNA-H4, and having a bunch of unmarked toroid
cores (some with windings, some without), I'd sure be interested in hearing
more about how you do this...

Check this link (if it works!)

It's supposed to be an article by w6rmk, on his earthlink web site. Which I can't find directly - must have gotten the page thru facebook.

Or google "Identifying Mystery Ferrites", which might get you there.

Also find a PDF by Owen Duffy, on his web site, the article "A method for estimating the impedance of a ferrite toroidal inductor at RF". Section 3, on the second page, is "Identifying ferrite materials", with a chart. You find the frequency where a 1-turn coil's R=X and get the mix number from the chart.

There is a similar (but much shorter) page at

I have these articles printed out for easy access when I did some toroid checking.

Doug

On Sat, Jul 11, 2020 at 01:01 PM, igor-m wrote:

Change the include paths in the nanovna.h (H4 branch line 441) to

// SD Card support, discio functions for FatFS lib implemented in ili9341.c
#ifdef __USE_SD_CARD__
#include "../FatFs/ff.h"
#include "../FatFs/diskio.h"
..

and it builds then.

Upload this fix, thanks

Change the include paths in the nanovna.h (H4 branch line 441) to

// SD Card support, discio functions for FatFS lib implemented in ili9341.c
#ifdef __USE_SD_CARD__
#include "../FatFs/ff.h"
#include "../FatFs/diskio.h"
..

and it builds then.